Semiconductor components, such as bare dice, chip scale packages, BGA devices and wafers can include terminal contacts in the form of bumped contacts. This type of component is sometimes referred to as a “bumped” component (e.g., bumped die, bumped wafer).
The bumped contacts provide a high input/output capability for a component, and permit the component to be surface mounted, or alternately flip chip mounted, to a mating substrate, such as a printed circuit board (PCB). Typically, the bumped contacts comprise solder balls, which permits the components to be bonded to the mating substrate using a solder reflow process. For some components, such as chip scale packages and BGA devices, the bumped contacts can be arranged in a dense array, such as a ball grid array (BGA), or a fine ball grid array (FBGA).
For performing test procedures on bumped semiconductor components it is necessary to make temporary electrical connections with the bumped contacts. Different types of interconnects have been developed for making these electrical connections. For example, a wafer probe card is one type of interconnect that is used to test semiconductor wafers. Another type of interconnect, is contained within a carrier for temporarily packaging singulated components, such as bare dice and chip scale packages, for test and burn-in. The interconnects include contacts that make the electrical connections with bumped contacts.
One problem with making these temporary electrical connections is that the sizes of the bumped contacts on a component can vary. Some bumped contacts can have a larger diameter and a greater height than other bumped contacts on the same component. Also, if the interconnect is used to test different components the sizes of the bumped contacts can vary between components. The interconnect contacts may not be able to accommodate these size differences, making reliable electrical connections difficult to make. This problem is compounded because the interconnect contacts must penetrate native oxide layers on the bump contacts to make low resistance electrical connections.
Another problem with bumped contacts particularly solder balls, is that the contacts deform easily during handling and testing, especially at elevated temperatures. For performing test procedures, it may be difficult to make low resistance electrical connections with deformed contacts. Specifically, the contacts on the interconnect may not adequately engage and penetrate the surfaces of the bumped contacts unless large contact forces are employed. However, the large contact forces can also deform the bumped contacts. For subsequent bonding procedures, deformed contacts can make alignment and bonding of the component with a mating substrate more difficult. In addition, deformed contacts are a cosmetic problem that can adversely affect a users perception of a semiconductor component.
The present invention is directed to an interconnect for making temporary electrical connections with semiconductor components having bumped contacts. The interconnect includes contacts constructed to electrically engage the bumped contacts, and to accommodate variations in the size and planarity of the bumped contacts.